Dogs Sniff Out Early-Stage Human Cancer

Ovarian cancer is often deadly because it is typically diagnosed only in late stages.

A new study suggests dogs could help doctors sniff out the disease earlier.

Scientists have shown previously that dogs seem able to sniff out cancer. A 2004 study in the British Medical Journal found dogs could detect bladder cancer by sniffing human urine. And in a small study in 2006 reported in the journal Integrative Cancer Therapies, dogs were trained to identify lung or breast cancer.

In the new study, researchers trained dogs to distinguish different
types and grades of ovarian cancer, including borderline tumors. Turns
out the odor of ovarian cancer does seem to differ from those of other
gynecological malignancies, such as cervical or endometrial cancers.

Importantly, early-stage and low-grade ovarian cancers emit the same scent as advanced tumors.

"Our study strongly suggests that the most common ovarian carcinomas
are characterized by a single specific odor detectable by trained
dogs," write the authors in the June issue of Integrative Cancer Therapies.
"And while we do not believe that dogs should be used in clinical
practice, because they may be influenced during their work, leading to
changes in the accuracy rates, still, under controlled circumstances,
they may be used in experiments to further explore this very
interesting new property of malignancies."

Dogs have many times more smell-sensitive cells in their noses
compared to humans. They can of course sniff out bombs, drugs and even buried corpses. In fact, animals have many amazing abilities to sense things that humans cannot.

The work was led by Dr. György Horvath from the University
Hospital in Göteborg, Sweden, with help from the Working Dog Clubs in
Sweden and Hungary.

"I believe there is great value in this study, which adds to the
growing body of research suggesting the diagnostic skills of these
specially trained dogs," said Dr. Keith I. Block, editor-in-chief of
the journal. "Their ability to detect specific odors associated with
chemicals related to malignancy should eventually lead to effective
methods and tools for very early detection, and thus a greater
proportion of cancer cures."

Ovarian cancer is three times as deadly as breast cancer.
Separately, researchers at Yale School of Medicine announced in
February a new blood test that detects ovarian cancer with 99 percent
accuracy. That ongoing research is in clinical trials now.

Rob was a writer and editor at Space.com starting in 1999. He served as managing editor of Live Science at its launch in 2004. He is now Chief Content Officer overseeing media properties for the sites’ parent company, Purch. Prior to joining the company, Rob was an editor at The Star-Ledger in New Jersey, and in 1998 he was founder and editor of the science news website ExploreZone. He has a journalism degree from Humboldt State University in California.